1. Basic Hydraulics: Solids Transport

2. What is sediment? Matter that settles to the bottom of a liquid Matter transported by water or wind May be particles that are derived from rocks, biological materials, or chemical precipitates Highway sediments may be a mix of materials, including pavement dust, natural soils, vehicle rust particles, tire dust particles.

3. Soil erosion (scour) Caused by impact and dislodgment of individual soil particles by rain drop impact. Caused by flow of water over soil surfaces. Caused by movement of water in channel systems.

4. Erosion and transport mechanisms Rill and sheet erosion Gully erosion Bed and bank erosion Suspended material transport Bed material transport Wash load transport Rill erosion progressing to gulliesAustralian Dept. of Environment

5. Suspended material transport Channels accumulate sediment from sheet/rill and gully erosion Lighter sediment carried as suspended material Heavier materials settle to bottom, added to material eroded from banks and bed

6. Bed material transport Stream bed load is part of total sediment load that moves along bottom of channel Sediment particles roll, bounce, or slide along bottom When stream has ability to re-suspend, some of particles will move When it loses ability to carry particles in suspension, they will drop out again Depends on local stream velocity and settling velocity of individual particles

7. Wash material transport Material that tends to flow through a reach without significant interaction with the bed Material is usually coarse sand, smaller in size

8. Solids transport – bed & suspended load El Paso District

9. Solids transport – bed & suspended load Terrell County

10. Solids transport – debris Also have bouyant solids (debris) in the flow